Apparatus for the manufacture of moulds, hollow cores and the like for foundry purposes



G. JENKINS L%[834,074

uRPosEs May 13, 1958 APPARATUS FOR THE MANUFACTURE OF MOULDS, HOI..

CORES AND THE LIKE FOR FOUNDRY P Filed July 1l, 1955 2 Sheets-SheetI l May 13, 1958 G. JENKINS 2,834,074

APPARATUS FOR THE MANUFACTURF. oF MouLDs. HoLLow CORES AND THE LIKE FCR FOUNDRY PURPOSES Filed July 1l. 1955 2 Sheets-Sheet 2 v w A A W A ,wn LL APPARATUS non' THE MANUltjnc'ruin: on Montos, noLLow Cones. AND 'THE LukaV Fon'FoUNnar PURPOSES Gwynville Jenkins, Staines, England, assigner t Polygram. Casting Company Limited,v Victoria, Englanda Britsh'rcompany This invention. relates to apparatus fontheernanufacture of moulds, hollow'cores and the'like for foundry purposes andi ha's'p'a'rticular reference' to apparatus for the' manufacture' of such articles by the process: known-- as' shell moulding.

In tiatpr'o'cess a metal pattern is heated to a suitable temperature and. is then coated with a stripping agent; A` moulding mixture comprising','ajrefractory granular material suchV as sand and' a relatively small quantity of a thermosetting resin binderis then applied t'othe'heated pattern' anda coating of themixture forms'on the plate; AfterV further heat treatment necessary'to produce optirnum` strength the coating lis'then removed from the pattern. Despite the use of the strippingagent the removal of the coating is not easy as it is usually necessaryto make use of ejectorpins to effect removal ofthe coating. The ejector pins must passthrough'the pattern and it is therefore important that movement of the pins should' beprevented during the formation of the coating which would be damaged` if movement of the pinsY occurredibefor'ethe coating was completely set.

One method of applying the moulding mixture to a pattern consists of inverting the latter and placing it over the mouth of a mixture containing bin. The bin with the pattern are then inverted so that moulding mixture within the bin falls onto the pattern. Inversion of the pattern may result in movement of the ejector pins relative to the pattern and damage to the coating may be caused.

It is an object of the present invention to provide apparatus for the manufacture of moulds, hollow cores and the like for foundry purposes in which movement of ejector pins which might cause damage is prevented by means not involving the use of springs whose efficiency rapidly becomes impaired due to continued exposure to heat.

According to the present invention in apparatus for the manufacture of moulds, hollow cores and the like for foundry purposes in which physical movement of a pattern takes place during the formation of the mould, hollow core or the like which is later separated from the pattern by means of ejector pins means are provided which prevent movement of the ejector pins relative to the pattern during that physical movement, the means being rendered operative by said physical movement during the cornmencement thereof, and inoperative on the return of the pattern to its original position.

In one embodiment of the invention in which several ejector pins are mounted in an ejector plate normally positioned beneath the pattern the means consists of a pivoted locking plate which is moved into a position in which the movement of the ejector plate towards the pattern is prevented during movement of the latter. Movement of the locking plate may be effected by means of a catch plate which co-operates with projections on a fixed part of the machine past which the catch plate moves.

Apparatus embodying the invention will now be de- 2,334,074 Patented May 13, 19158 2 scribed in greater' detaily by wayl of' example and with reference. to `the accompanying drawings,- of which:

Fig.- l is ay sideelevation of' part'of the apparatus, and

Fig. 2 is `an front'elevation of the'sarnepart,

Figs. l' and 2 show only suicient ofthe lstructure of the machine as is'necessary` forv an understanding ofthe invention. That` structure includes two\ uprights 1 to which are pivoted at 2a arms 2 whichsuppo'rt a pattern plate 3 to' which a pattern (not shown) can be secured'. The pattern platev is apertured to receive'ejector pins of which one, 4, is shown and whoseprecise dispositions will depend on the configuration of" the mould'or core which is to be produced. Each ejector pin 4' is secured at its lower` end' as viewed in Figs; l and A2in an' ejector plate 5 operated by-rods 6 guided by a member 7 being partof the structure of the machine.

Secured to the undersurface (a's'viewed in the figures) of theVv pattern plate 3 and adjacent to opposed sides of it are mounting blocks 8 between which a shaftv9 is rotate ably supported. Secured to the shaft 9 between the blocks 8 is a locking plate 10. Also secured to the shaft 9 at one end is a catch 11? whose shape iscl'early shown in Fig. 1. p

Projecting from brackets l'secured totheuprights' 1 are studs or pins 13` and 14. It' will be observed Y'from Fig. 1 that the same vertical plane passes through` the vshaft 9 and pin 13 andthe same horizontalplane'v through shaft'9 and pin 14.

During the formation of a'rnou'ld', hollo\v"core orthe like-itis' necessary toswing the pattern plateA and ejector plate in the direction of arrow 15' intothe-position shown in' dotted lines on Fig'. 1`. In this position the pattern plate 3 lies over the mouth of a bin 16 containing moulding mixture;

A pattern when attached to the pattern plate 3 lies within the bin 16 when the parts are in the position shown in Figure l in rdotted lines. To invest the pattern, the bin 16 is inverted and moulding mixture in the bin falls onto the pattern. Excess mouldng mixture falls away from the pattern when the bin is righted. During the inversion of the bin 16 with the pattern plate, the arms 2 disengage the uprights 1 at the pivot points 2a. l

During the commencement of the swinging movement the nose 17 of the catch 11 comes into contact with the stud 14 and the' continued swing of the pattern plate causes the catch 11 and the'v locking plate 10 to move clockwise as viewed in Fig. l until the nose 17 is clear of the stud 14. Clearance isnot obtained until the locking plate 1l) is in a position such that the liats 18 and 19 -at each end of the plate are in contact with the pattern plate and ejector plate respectively and movement of the ejector plate towards the pattern plate is thus prevented. As the ejector plate cannot move away from the pattern plate it is lixed relative thereto. t f

On return of the pattern plate'to the position shown in Fig. 1 in full lines the surface Ztlof the catch 11 comes into contact with the stud 13 .and the catch and locking plate move in an anticlockwise direction as seen in Fig. l and the locking plate in thus moved into a position in which the ejector plate is free to move.

It will be `appreciated that the movement of the ejector plate necessary to operate the ejector pins when it is desired to eject a mould, hollow core or the like from the pattern is not impeded by the catch or the locking plate as the latter can both swing as the ejector plate moves towards the pattern plate.y The catch has in fact a cut away part 21 so that there is no contact between the catch and the pin 14 during the ejecting movement of the ejector plate.

It will be understood that the invention is not limited to machines in which the swinging movement of the pattern plate described above is incorporated but may be used in machines where other kinds of movement take place.

I claim:

l. Apparatus for the manufacture of moulds, hollow cores and the like for foundry purposes comprising in combination, upright support means, arms pivotally mounted on said support means, a pattern plate mounted between said arms, ejector pins passing through said pattern plate, an ejector plate mounted below said pattern plate for operating said pins, locking levers lpivotally mounted on said pattern plate for locking said ejector plate against movement relative to said pattern plate and releasing means secured to said upright support means for releasing said locking levers from locking engagement with said ejector plate and said pattern plate.

2. Apparatus for the manufacture of moulds, hollow cores and the like for foundry purposes comprising in combination,` upright support means, arms pivotally mounted on said support means, a pattern plate mounted between said arms, ejector pins passing through said pattern plate, an ejector plate mounted between said upright support means and below said pattern plate for operating said pins, rotatable locking ievers pivotally mounted upon said pattern plate, fixed projections secured to said upright Support means for engagement with said locking levers on movement of said pattern plate from and into an ejection position to move said locking levers into and out of a locking position between said pattern plate and said ejector plate.

3. Apparatus for the manufacture of moulds, hollow cores and the like for foundry purposes comprising in combination a pattern plate, a support for said pattern plate which is movable relative to said support, ejector ins passing through said pattern plate, an ejector plate for operating said ejector pins, locking means rotatably mounted between said pattern plate and said ejector plate and actuating means for said locking means secured to said support for moving said locking means into a locking position between said pattern plate and said ejector plate on movement of the former from an ejection position and out of said locking position on return of said pattern plate to said ejection position.

4. Apparatus for the manufacture of moulds, hollow cores and the likefor foundry purposes comprising in combination a pattern plate, a support for said pattern plate which is movable relative to said support, ejector pins passing through said pattern plate, an ejector plate for operating said ejector pins, locking levers pivotally mounted on said pattern plate for preventing movement of said ejector plate relative to said pattern plate, releasing levers pivotally mounted on said pattern plate for synchronous movement with said locking levers for releasing the latter from locking engagement with said ejector plate and said pattern plate, and means secured to said support for moving said locking levers into and out of locking engagement.

5. Apparatus for the manufacture of moulds, hollow cores and the like for foundry purposes comprising in combination, upright .support means, arms pivotally mounted on said support means, a pattern plate mounted between said arms, ejector pins passing through said pattern plate, an ejector plate mounted between said upright support means and below said pattern plate for operating said pins, locking levers pivotally mounted on said pattern plate for locking said ejector plate against movement relative to said pattern plate, a releasing lever for each locking lever and coupled thereto, and studs secured to said upright support means for moving said locking levers into and out of locking engagement.

References Cited the le of this patent UNITED STATES PATENTS 2,669,759 Valyi Feb. 23, 1954 2,691,195 Daugirdas Oct. l2, 1954 2,778,074 Zimmerman Jan. 22, 1957 

